Converting fixed fields text record to JSON can be realized in many ways. A solution can be the using of a REST Service combined with the Fixefid java library.
The environment is as a follows:
- Java 8
- Spring Boot 2.3.4.RELEASE
- Spring Web
- Fixefid 1.1.0
- Spring Doc Openapi 1.5.0
The Fixefid java library permits to define a fixed fields text record with Java Bean or Java Enum. In this case the definition by Java Bean can be used to annotate a resource representation class of a REST Service.
For instance, we want converting a customer record like this one:
String record = "0000000000000000001Paul Robinson ";
to a json object like this one:
{
"id": 1,
"firstName": "Paul",
"lastName": "Robinson"
}
To model the customer representation, we can create a resource representation class:
@FixefidRecord
public class Customer {
@FixefidField(fieldLen = 19, fieldOrdinal = 0, fieldType = FieldType.N)
private Long id;
@FixefidField(fieldLen = 50, fieldOrdinal = 1, fieldType = FieldType.AN)
private String firstName;
@FixefidField(fieldLen = 50, fieldOrdinal = 2, fieldType = FieldType.AN)
private String lastName;
protected Customer() {
}
public Customer(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
@Override
public String toString() {
return String.format("Customer[id=%d, firstName='%s', lastName='%s']", id, firstName, lastName);
}
public Long getId() {
return id;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
}
The resource representation class is annotated with the Fixefid annotations. Then we can create the record request:
public class RecordRequest {
private Long requestId;
private String record;
public String getRecord() {
return record;
}
public void setRecord(String record) {
this.record = record;
}
public Long getRequestId() {
return requestId;
}
public void setRequestId(Long requestId) {
this.requestId = requestId;
}
}
and the Customer response:
public class CustomerResponse {
private Long requestId;
private Long responseId;
private Customer customer;
public CustomerResponse(Long requestId, Long responseId, Customer customer) {
this.requestId = requestId;
this.responseId = responseId;
this.customer = customer;
}
public Long getRequestId() {
return requestId;
}
public void setRequestId(Long requestId) {
this.requestId = requestId;
}
public Long getResponseId() {
return responseId;
}
public void setResponseId(Long responseId) {
this.responseId = responseId;
}
public Customer getCustomer() {
return customer;
}
public void setCustomer(Customer customer) {
this.customer = customer;
}
}
last, the rest controller:
@RestController
public class CustomerController {
private final AtomicLong counter = new AtomicLong();
@PostMapping(path = "/recordtocustomer", consumes =
"application/json", produces = "application/json")
public CustomerResponse recordToCustomer(@RequestBody RecordRequest
request) {
Customer customer = new Customer(null, null);
new BeanRecord(customer, request.getRecord());
return new CustomerResponse(request.getRequestId(),
counter.incrementAndGet(), customer);
}
}
With Postman we can test the service:
Here the project of the example on github.
Giancarlo Parma 